The present invention relates to circuit breakers, and, more particularly, to a means for resetting an operating mechanism latch which will not impede the trip time of the operating mechanism.
Circuit breaker operating mechanisms are used to control the opening and closing of separable contacts within a circuit breaker system. These operating mechanisms utilize linkage arrangements to translate the potential energy of biased springs into an output force required to quickly trip the circuit and separate the contacts in the event that a fault condition occurs.
In the prior art circuit breaker operating mechanisms, a torsion spring is typically used to bias two cooperative elements during the resetting of the latching system. For example, in U.S. Pat. No. 4,001,742 entitled "Circuit Breaker Having Improved Operating Mechanism", a torsion spring biases a primary latch in a counterclockwise direction about a pivot point of the primary latch while also biasing a secondary latch in a clockwise direction about a pivot point of the secondary latch thereby bringing both latches into latching engagement with each other. In the resetting operation of this system, however, the force of the torsion spring is a factor in the interengagement of the latches, and the time required of the mechanism to overcome that force may be significant.
While the torsion springs of the prior art systems adequately allow the elements of the latch linkage system to interengage and reset the operating mechanism, the latch linkage components must be displaced by the operating mechanism prior to the separation of the contacts. In low force output systems, this displacement requires a significant amount of time. The use of a torsion spring, therefore, the force of which must be overcome in the tripping operation, significantly increases the amount of time needed to separate the breaker contacts. An operating mechanism is needed that reduces the amount of time needed to trip the circuit breaker operating mechanism thereby allowing for faster separation of the breaker contacts.